Texas has many people of Mexican descent, but there are also increasing numbers of Guatemalans in Texas. According to the post below, Guatemalans in far west Texas are called “blue tarp Mexicans” because they travel home to Guatemala (crossing through Mexico) in vehicles overloaded with items and covered with blue plastic tarp.  This term is not otherwise attested on the internet, but could have a west Texas currency as indicated.
 
 
Lonely Planet Forums
RichTX1
18-Jan-2008 14:39
RE: Nicknames for Foreigners - Gringo, Farang, etc.
Actually, “gringo” is a variant of “grego” ... Greek (as in Greek Orthodox, as opposed to Roman Catholic) and has been used in Spanish since the middle-ages to mean any foreigner of vaguely similar culture. In Chile, it can mean a Portuguese-speaking Brazilian. In Mexico, it doesn’t mean a U.S. citizen, but almost any foreigner from North America or Europe (or, for that matter, Australians and Kiwis, as well).
 
Here in far west Texas, Guatemalans are called “blue tarp Mexicans”—because Guatemalans are so often driving thru the area going home, via Mexico, towing a second car stuffed with a little of everything, and more stuff on the roof covered with a blue plastic tarp.